In order to accomplish reliable and valid research into the characteristics and mechanisms of Alzheimer's disease (AD) and related dementias, it is imperative to have data available from a well- characterized cohort of patients, with longitudinal follow-up to provide information on the course of the disease. The cohort should have a broad range of levels of education and socioeconomic status, as well as racial diversity. The cohort should contain patients with varying levels of disease severity, in order to provide subjects for studies requiring mild, moderate, or severe AD. Further, a system must be in place for the prospective entry of new patients and age-equivalent control subjects into a registry to be available for future research studies. The Clinical Core of the Alzheimer's Disease Research Center fulfills these functions for the University of Pittsburgh ADRC. The purpose of this Clinical Core is to provide evaluation and follow-up to patients and control subjects enrolled through the Memory Disorders Clinic and followed in the ADRC Registry. Specifically, the Core provides a detailed evaluation of all patients/control subjects at study entry, and annual re-evaluations until the patient/subject drops from the project or dies. The Core also strives towards maximal participation in the autopsy program of the ADRC by providing longitudinal follow-up to these patients and control subjects. The Clinical Core is also responsible for providing clinical data, research subjects (patients and controls), and technical and scientific leadership for support of new and ongoing research at the University of Pittsburgh ADRC and associated local, regional, national, and international studies. Finally, the ADRC will continue outreach programs developed during the past three years to provide care and support for members of the medically underserved inner-city and rural populations of Western Pennsylvania. The ADRC established a satellite clinic, the Alzheimer Outreach Center, in the predominantly African American Hill District of Pittsburgh during the current funding period. Patients seen in the AOC Clinic evaluated and enrolled in the ADRC Registry in the same manner as the patients at the University Memory Disorders Clinic, increasing the number of African American controls and patients in the Registry. Special programs to educate the African American Community on the value of autopsy are part of this program. External confirmation of the accuracy of the clinical diagnosis of AD is vital to assure that the diagnostic procedures employed by the Clinical Core are appropriate. Autopsy confirmation of a clinical diagnosis of Probable AD was greater than 90% for all cases from the ADRC coming to autopsy since inception of the Center.